Department of Pediatric Dentistry, School of Dentistry, Universidade de São Paulo, Av. Lineu Prestes, 2227, Cidade Universitária, São Paulo 05508-000, Brazil.
Microsc Microanal. 2013 Dec;19(6):1445-9. doi: 10.1017/S1431927613012725. Epub 2013 Aug 15.
This study compared dentinal tubule density and diameter of human primary and permanent teeth at different depths of the coronal dentin. Crowns of eight primary second molars and eight permanent third molars were serially sectioned into three disks of ~0.5 mm thickness (superficial, middle, and deep layers), perpendicular to the long axis. Tubule density and diameter were evaluated in 2,000× and 3,000× magnifications by scanning electron microscopy. Data obtained were subjected to two-way repeated measures ANOVA and Tukey's post hoc test (α = 0.05). Tubule density was greater in primary teeth compared with permanent ones, regardless of depth (primary: 124,329 ± 43,594 mm2; permanent: 45,972 ± 21,098 mm2). In general, the tubule density increased as the dentin depth increased, except to the superficial and middle layers from permanent teeth. Tubule diameter was larger in the dentin layer close to the pulp chamber (superficial: 2.4 ± 0.07 μm; middle: 3.70 ± 0.06 μm; deep: 4.28 ± 0.04 μm). No difference was observed between primary (3.48 ± 0.81 μm) and permanent teeth (3.47 ± 0.73 μm). The tubule diameter increases as the dentin depth increases for primary and permanent teeth; however, the tubule density is higher in primary teeth.
本研究比较了人乳牙和恒牙牙冠不同牙本质深度的牙本质小管密度和直径。将 8 颗乳牙第二磨牙和 8 颗恒牙第三磨牙的牙冠连续沿牙长轴方向切成 3 个约 0.5mm 厚的圆盘（表层、中层和深层）。使用扫描电子显微镜在 2000×和 3000×放大倍数下评估小管密度和直径。通过双向重复测量方差分析和 Tukey 事后检验（α = 0.05）对获得的数据进行分析。无论深度如何，乳牙的小管密度均大于恒牙（乳牙：124329 ± 43594mm2；恒牙：45972 ± 21098mm2）。一般来说，随着牙本质深度的增加，牙本质小管密度增加，但恒牙的表层和中层除外。靠近牙髓腔的牙本质层的小管直径较大（表层：2.4 ± 0.07μm；中层：3.70 ± 0.06μm；深层：4.28 ± 0.04μm）。乳牙（3.48 ± 0.81μm）和恒牙（3.47 ± 0.73μm）之间未见差异。对于乳牙和恒牙，牙本质小管直径随牙本质深度的增加而增加，但乳牙的牙本质小管密度更高。
